Brú na Bóinne Complex’s three main prehistoric sites, Newgrange, Knowth and Dowth, lie on River Boyne’s northern bank,50 km north of Dublin. Boasting the largest and most important concentration of prehistoric megalithic art in Europe, the site also holds monuments of social, economic, religious and funerary functions. --WHMNet paraphrase from the description at WHC Site, where additional information is available.

Newgrange (Irish: Dún Fhearghusa) is one of the passage tombs of the Brú na Bóinne complex in County Meath, one of the most famous prehistoric sites in the world and the most famous of all Irish prehistoric sites. Newgrange is the oldest surviving building in the world and was built in such a way that at dawn on the shortest day of the year, the winter solstice, a narrow beam of sunlight for a very short time illuminates the floor of the chamber at the end of the long passageway. --Wikipedia. Text is available under the Creative Commons Attribution-ShareAlike License.